Joints of hollow beams



- Nov. 30, 1948.

JOINTS OF HOLLOW BEAMS Filed May 27, 1944 14 seer-o 50/9665,

A. BORGES 2,455,217 7 Patented Nov. 30, 1948 UNITED STATES PATENT OFFICE In Brazil Augu 3 Claims.

This invention relates to a beam and more specifically to a built-up wooden beam or joist. It is an object of the invention to so interconnect two parallel planks with a plurality of cross pieces to form a hollow beam which is useful in roof structures for large spans. The pieces comprising the beam may be readily cut and put together with a minimum of time and labor resulting in a strong structural member with a minimum requirement of timber.

A further object resides in the structure of the beam in which two parallel planks are interconnected with a plurality of pairs of cross members connected by dowel pins and reinforced and adjusted by a wedge member.

Another object of the invention resides in the method of constructing the beams in which rhomboid openings are cut in the planks, the cross members inserted in the openings and the members provided with dowel pins and finally adjusting the cross members by means of a triangular wedge member.

Further objects will be apparent from the following description when considered in connection with the accompanying drawing in which,

Figure 1 is a plan view of the beam,

Fig. 2 is a side elevation of a portion of the beam,

Fig. 3 is an end view partly in section of a detail,

Fig. 4 is a cross section of two cross members,

Fig. 5 is an end view of a part of the beam,

Fig. 6 is a side elevation of the entire beam,

Fig. 7 is an end view of the beam of Fig. 6, and

Fig. 8 is a perspective view of the beam as illus-- trated in Fig. 2.

As shown the beam comprises two spaced and parallel planks 9 and I and these planks are interconnected by pairs of cross members II and I2. These cross members project into rhomboid shaped holes or openings 13 in the planks 9 and I0 and as shown on the drawing the cross members are arranged in a plane at right angles relative to the width of the planks. At the inter section M of the pairs of cross members I l and I2 holes are bored into which dowel pins l preferably of wood are inserted. In the space between the crossed pairs of cross members and the planks a triangular-shaped wooden wedge member 16 is inserted and this wedge memberacts to adjust the joint l4 relative to the cross members.

Since the planks 9 and ID are built flat into the beam, the advantage is attained, particularly when wood is employed as the specific material, that the beam possesses maximum inertia both along a lateral horizontal axis as well as along the vertical axis. The momentum of inertia relative to the vertical axis is of further advantage in that greater spacing between weatherboards are permissible.

Thus a beam constructed according to this invention produces a structure which has less total height and greater momentum of inertia along the vertical axis.

As a further feature of the invention, the latter relates to the method of constructing the beam in which the planks 9 and ID are provided with rhomboid openings or holes 53, the cross members ll and 12 are then inserted in these holes 'with dowel pins 15 to strengthen the members and then inserting the wedge members 16 to strengthen the members.

I claim:

1. A beam comprising two spaced planks arranged parallel to each other and having a plurality of rhomboid-shaped openings therein, a plurality of pairs of cross members projecting in said openings and interconnecting the planks, said pairs of cross members being angularly arranged between the planks and crossing each other near each plank and forming a triangular space between the crossing and the plank, and a pin passing through and connecting the cross members at each crossing, the planks being arranged so that the widths thereof are face to face in the beam.

2. A beam according to claim 1 in which the pairs of cross members are arranged in zig-zag fashion longitudinally between the two spaced planks.

3. A beam according to claim 1 in which a wedge member is provided in the triangular space to reinforce the joint formed by the crossed cross members.

ALBERTO BORGES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 20,082 Morrison Apr. 27, 1858 64,340 Manley Apr. 30, 1867 1,391,122 Knudsen Sept. 20, 1921 1,445,026 McKeown Feb. 13, 1923 1,944,099 Mearkle Jan. 16, 1934 2,214,935 Perry Sept. 17, 1940 2,248,380 Pedersen July 8, 1941 FOREIGN PATENTS Number Country Date 25,918 Denmark 1920 71,608 Austria Aug. 25, 1916 79,604 Switzerland Apr. 1, 1919 

